Apparatus for grinding the contour edge of elongated bodies, in particular cutlery

ABSTRACT

An apparatus for grinding the contour edge of elongated bodies with at least one swivellable grinding unit which has a driven grinding tool pressable directly or indirectly onto the workpiece and a feeler roller controlling the pressure which may be moved along a pattern curve corresponding to the workpiece. A workpiece holder is mounted on a movable base in such a way that it can be moved past the grinding unit for the processing of a longitudinal edge.

United States Patent [191 Oberlander et al.

[ Oct. 23, 1973 I APPARATUS FOR GRINDING THE CONTOUR EDGE OF ELONGATED BODIES, IN PARTICULAR CUTLERY [75] Inventors: Karl O. Oberlander; Hugo Febler,

both of Geislingen; Hans Schmacher, Schlosshalde; Karl Widenhofer, Kuchen, all of Germany [73] Assignee: Wurttembergische Metallwarenfabrik, Geislingen/Steige, Germany [22] Filed: Jan. 13, 1972 [21] Appl'. No.: 217,527

[30] Foreign Application Priority Data Jan. 15,1971 Germany P 21018519 [52] US. Cl. 51/145 T, 51/215 AR [51] Int. Cl B24b 21/02 [58] Field of Search...... 51/215 AR, 145 R, 5l/145 T, 100 11,108,134, 237 T [56] References Cited UNITED STATES PATENTS 765,304 7/1904 Bishop 51/100 R X 957,515 5/1910 Nichols 51/108 R X 2,252,594 8/1941 Carlson 5l/2l5 AR X 2,741,076 4/1956 Jordan 5l/237 T X 2,855,730 lO/l958 Ferguson 5l/l45 R Primary ExaminerDonald G. Kelly Assistant Examiner-Howard N. Goldberg Att0rney-Woodhams, Blanchard and Flynn [57] ABSTRACT An apparatus for grinding the contour edge of elongated bodies with at least one swivellable grinding unit which has a driven grinding tool pressable directly or indirectly onto the workpiece and a feeler roller controlling the pressure which may be moved along a pattern curve corresponding to the workpiece. A workpiece holder is mounted on a movable base in such a way that it can be moved past the grinding unit for the processing of a longitudinal edge.

18 Claims, 7 Drawing Figures Patented Oct. 23, 1973 6 Shasta-Sheet :3

Patented Oct. 23, 1973 3,766,689

6 Sheets-Sheet 5 Fig.3

Patented Oct. 23, 1973 6 Sheets-Sheet 4 Patented 'Oct. 23, 1973 3,766,689

7 6 Sheets-Sheet 5 The invention relates to an apparatus for grinding the contour edge of elongated bodies, in particular hollow ware, and cutlery, with at least one swivellable grinding unit which has a driven grinding tool pressable directly or indirectly onto the workpiece and a feeler roller controlling the pressure which may be moved along a pattern curve corresponding to the workpiece, and a workpiece holder mounted on a movable base in such a way that it can be moved past the grinding unit for the processing of a longitudinal edge.

An apparatus of the type described hereinabove is known, in which a fixed item of cutlery can be moved along its longitudinal direction between two band units with horizontal bands. The guiding of the contact rollers pressing the bands on the item to be processed by means, in each instance, of a feeler roller controlled by a pattern permits of a good processing of the longitudinal sides of the fixed workpiece. However, with this apparatus, it is not possible to process the contour edge sections at the front ends. These must be ground manually. This requires skilled personnel and as a consequence substantial manufacturing costs.

Furthermore an apparatus is known in which a fixed item of cutlery is moved past a vertically driven grinding band along the direction of its longitudinal axis. With this method also no machine processing of the front ends is possible. In addition, grinding scores develop on the processed edge which are very difficult to eliminate.

The object of the invention is to construct an apparatus of the type described at the beginning in such a way that it permits of the mechanical processing of the entire contour edge of a workpiece in an operation substantially automatically controlled by simple means.

The problem is. solved by the invention in that the movable base is constructed as a rotating platform and at least two grinding units are arranged within its confines in such a way that each grinding tool processes in addition to a longitudinal edge also in each instance at least half of each front edge, in that the worpiece holder is swivellable about a vertical axis in its mounting on the rotating platform. and in that on rotation of the platform there are provided positively cooperating guide members for a swivelling of the workpiece holder by about 180 at least within the area between the two grinding units.

With this apparatus it is possible to process an elongated body on its contour edge and all around, without the need of fixing it and/or having recourse to manual working. Considering the complex pattern of movement the apparatus is constructed very simply. No drives with directional changes are necessary, but on the contrary the swivelling motion of the workpiece holder is effected by the guiding members only through the continual rotation of the rotating platform. However, the construction of a continuous rotation drive is simple. In addition the tool need not be readjusted during processing, as a result of which an advantageous reduction of the down times is obtained. As a result of the simple construction the entire apparatus is advantageously free from breakdowns and requires only little maintenance.

A very advantageous method of operation of the apparatus according to the invention may be attained in that several grinding units are mounted pairwise within the confines of the rotating platform at are distance from one another, and in that a number of workpiece holders corresponding at least to the number of grinding units are mounted on the rotating platform at corresponding distances, and'further in that corresponding guide members are-provided. By this means several advantages are obtained. At one and the same time it is possible to process as many workpieces as there are grinding units, and in fact in each case one workpiece on its first side, and a workpiece already processed on one side, on its second side. Furthermore it is possible with this apparatus to process one workpiece after another on processing stations performing different operations without readjustment and without interruption of the continuous rotary movement of the platform, the number of operations being determined by the size of the rotating platform and by the number of grinding unit pairs mounted thereon. For example, it is possible to provide in succession a grinding unit for coarse grinding, one for fine grinding and one for polishing. Then it is possible to process six workpieces at the same time. As for the entire cycle only a once-only adjustment is necessary, there is an economical reduction of the working time required for the purpose.

Advantageously, to form a fixing and removal station on the rotating platform, the number of workpiece holders exceeds by at least one that of the grinding units and corresponding guide members are associated with it. It is therefore not necessary to interrupt the rotary movement of the platform and thereby the onward transport of the workpieces when a finished workpiece is removed and a new one is mounted. At a place within the confines of the rotating platform that is free from grinding units and provides room for an operator, the guide members for the workpiece holder may be so disposed that the workpiece holder occupies an advantageous position on the circumference of the rotating platform for the removal and insertion of workpieces.

In a preferred method of execution of the apparatus according to the invention curved tracks are stationarily mounted as guide members within the range of the rotating platform, and also a guide roller guided at least along a section of the curved track is mounted in the workpiece holder at a distance from its swivelling axis. The guide roller is therefore guided on two sides in the curved tracks. Thus, the guide is a positive guide which is free from breakdowns. Furthermore, the walls of the curved tracks can absorb the pressure that is transmitted within the zone of contact of a grinding unit from the workpiece holder to the guiding roller.

A curve section with a turning point constructed as a switch point can in each case be provided within the range of a pair of x grinding units for swivelling the workpiece by some between two processingpositions. Advantageously, the switch point has as a tongue a spring-loaded piece of curve pivotable by the guide roller against the action of the spring. Each workpiece holder sets its path for itself therefore during its movement of rotation. The spring takes care that after the guide roller has rolled by the piece of curve reassumes its original position.

A satisfactory guiding of the guide roller also within the range of the switch point is obtained in simple manner in that the piece of curve is divided at its free end into an upper and a lower point and in that the points are spread out horizontally away from each other. Thus, as it runs into the switch point, the guide roller runs along the curve formed by one, for example the upper point, and after it has run through the switch point, when the piece of curve is again in its basic position, for example along the curve formed by the lower point. By this means the positive two-side guiding of the roller is assured also within the range of the switch point. That is important for the case when, as a consequence of the shape of the workpiece and of its size, and/or of the arrangement of the grinding units, the guide roller finds itself in the vicinity of the switch point tongue, while a lateral processing pressure is still or again exerted by a grinding unit.

An economic construction anda simple manufacture of an apparatus with severalprocessing stations on a rotating platform make it necessary to design the curve track sections associated with the various pairs of grinding units congruent with one another. Thereby, between these pairs of grinding units, a swivelling back of the workpiece holder to the starting position is necessary. During this swivelling movement no lateral pressure is exerted onto the workpiece holder and thereby onto the guide roller. It is therefore in fact possible, but not absolutely necessary, to compel the swivelling movement over a relatively appreciable portion of switch point of a curve track. In a preferred method of execution of the apparatus according to the invention, stationary bolts are vertically mounted in the area between the curved track sections, and in each case a recess is arranged, passed over these bolts, movable and rotatable around the workpiece holder for the swivelling thereof, on the workpiece holders. The guiding for the pushing over of the recess (clearance) on the bolts is effected still from the end of the preceding curve section. As soon as the recess has been pushed over the bolt and the guide roller leaves the portion of curved track, the further rotation of the table entraining the workpiece holder effects the swivelling of the latter about the bolt at least until the guide roller has movedinto the beginning of the next curved track section. It then takes over again the guiding of the workpiece holder, as a result of which the recess comes off the bolt. The recess may advantageously be composed of a longitudinal slit, open at least on one side, on. a guide roller bearer. Thereby the longitudinal slit is lo cated more or less at the level of the guide roller, i.e., the bolt may be arranged at the same height as the adjoining curve sections, if need be on the same base. The necessary exact association between the bolt and the adjoining ends of the curve tracks, and also the just as important association between the longitudinal slit and the guide roller are in this way made and controlled in the most simple manner.

The arrangement of the workpiece holder on the rotating platform can be effected in simple manner by means of a support rotatably mounted about a vertical axis which is rigidly connected over the rotating platform with the workpiece holder and under the rotating platform with a guiding roller carrier supporting the guiding roller. Thereby it is possible to mount the curved tracks and the bolts for swivelling in simple manner firmly on the platform chassis, for example on a plate over which the rotatingplatform through which the supports pass moves. This itself does not need in any way to be a closed plate; it may also be in the form of a spider, the ends of the spider bearing in each case a workpiece carrier and its fittings.

In a preferred mothod of execution the support has an U-shaped bend, the lower leg of which constitutes the guide roller bearer and the upper leg of which extending along the same direction as the lower one, and bears the workpiece holder in equally similar longitudinal direction over the guide roller bearer. This arrangement has the advantage that the guide roller bearer and the workpiece holder move in similar manner, and therfore not even once does a transmission of the movement take place, which simplifies the construction of the curved tracks and the adjustment of the grinding tools. Furthermore, as a consequence of this lateral shift of the workpiece holder in relation to the rotating axis on the rotating platform, there is obtained a more favorable distribution of force, in particular a release of the bearing on the rotating platform from the lateral processing pressure.

The upper leg of the support is advantageously adjustable in length depending upon the size of the workpiece. By this means it is made possible to arrange workpieces of different lengths on the guide roller bearer in such a way that their front edges on both sides can be positively processed on swivelling. If required, an additional adjustment of the grinding units is possible.

The workpiece holder requires a work-locating fixture. In this connection the difficulty arises that the work-locating fixture must rotate with the rotating platform, not impede the swivelling movement of the workpiece holder and never get in the way of the grinding unit. In an advantageous further embodiment of the invention, therefore, the workpiece holder is associated with a stirrup gripping it substantially in the form of a C which is rotatable with its legs on the workpiece holder about a vertical axis and is rotatably mounted on the rotating platform about a guided vertical axis displaceable longitudinally. The C-shaped stirrup thus cooperates with the. workpiece holder in the form of a sliding crank gear, its bearing on the rotating platform constituting the crosshead.

The workpiece holder with the U leg of the support is in this case the crank which, moreover, does not perform 'a complete circular movement, but only a to and fro swinging oscillatory movement. It is obtained in this manner that the substantially vertical connection member of the C-shaped stirrup is always located in the direction of the inside of the rotating platform, and thus outside the gripping range of the grinding unit. In this connection the longitudinal shifting on the rotating platform takes place radially to its rotating axis.

A secure holding of the workpiece may be obtained in simple manner in that the workpiece holder is provided with interchangeable form halves which raise the workpiece as far as an edge positioned above and all around. The going over from one workpiece form to another is therefore possible by the simple exchange of form halves.

To guide the feeler roller controlling the grinding tool the pattern may be mounted on the workpiece holder in alignment with its form halves. When the form halves are changed the pattern is also changed just as simply.

Further details of the invention will be supplied by the description of methods of execution which are shown in the drawing in which:

FIG. l is an apparatus for grinding the contour edge of elongated bodies in diagrammatic top view;

FIG. 2 is a cross-section of the apparatus according to FIG. 1 on an enlarged scale;

FIG. 3 is a diagrammatic representation of a workpiece movement in a part area according to FIG. 2;

FIG. 4 is a partly exploded view of the apparatus;

FIG. 5 is an enlarged side view of a part of the apparatus according to FIG. 4;

FIG. 6 is a greater detailed representation, and

FIG. 7 a section along line VlIVlI of FIG. 6.

As will be seen from FIG. 1, the apparatus for grinding the contour edge of elongated bodies has a rotating platform represented as a whole by l, which is formed as a spoked star with eight spokes 1a. Under the rotating platform there is mounted a stationary circular plate 2 concentrically with it, and rotatable opposite the rotating platform in the direction of the arrow a. In a complete revolution the end of each spoke 1a passes in the circumference range of the rotating platform through eight stations A to H arranged substantially correspondingly to the ends of the spokes. Within the area of the stations B to G a grinding unit 3 is arranged in each instance for the processing of a workpiece 4. In this construction the grinding units 3 are in each instance associated with one another in pairs in such a way that the grinding units 3a within the range of stations B and C are intended for coarse grinding, the grinding units 3b within the rangeof stations D and E for fine grinding, and grinding units 30 within the range of stations F and G for polishing. The workpiece 4 is mounted on station A at the extremity of spoke la and fixed by an operator during the continuous rotation movement of the rotating platform 1 between stations A and B, processed on its contour edge as it passes through stations B to G and taken off at station H after release of the clamping. Within the area of stations H and a working area not represented for an operator has been provided. An exact description of the processing operation follows later. A spoon 4 has been chosen as the workpiece 4.

On the circular plate 2, groove-shaped curved tracks 5 open at the top are arranged and in fact from the area of station H to the area of Station C in association, while in the areas of stations D and E and stations F and G a portion of curve is in each case arranged without connection with the others. Between the stations C and D, E and F and G and H, where no curve track runs, there has been mounted in each case a vertical bolt 6 on the circular plate 2. A guide roller 7 is associated with each spoke la in a manner still to be described in more detail below, the guide roller being I guided through the curved tracks by the rotary movement of the rotating table 1. At the free end of each spoke 1a a bearing 8 with vertical axis 8a is firmly mounted. The shaft 8a moves accordingly with the rotation of the platform along a circular path b (see FIG. 3). A workpiece holder is swivellably mounted about the shaft 8a in the bearing 8 by means of a support 9 only indicated in FIG. 2 and 5. The workpiece holder 10 can be seen as a whole in FIGS. 4 and 5, in FIGS. 1 to 3, for the sake of a better general view, only workpiece 4 has been represented, the contour of which generally covers the workpiece holder. The guide roller 7 is rigidly connected with support 9 and thus also pivotable about bearing 8a. The workpiece holder 10 has associated with it a work-locating fixture 11 with a C-shaped stirrup 12. The stirrup 12 is in each case represented in FIG. 2 in horizontal section. In this way its lower leg 12a is visible, it being connected with a bearing 13 (see also FIG. 4). With this bearing 13 the stirrup 12 is rotatable around the vertical shaft of the worklocating fixture 11. Furthermore, in FIG. 2, the vertical leg 12b of stirrup 12, in the form of a hollow box, has been represented in cross-section. A guiding arm 14 is solidly connected with the stirrup 12, this arm being fully shown in FIG. 2 in the area of station E. It has at its free end a longitudinal slit 15 by means of which it engages on a pin 16 centrally mounted on rotating table 1, in such a way that the guiding arm 14 is longitudinally displaceable and rotatable in opposition to pin 16. The guiding arms 14 associated with the other spokes 1a have been shown in each instance in exploded view only for the sake of greater clarity.

Each grinding unit 3 has a rotating grinding band 17. This is guided over a driving roller 18, two tensioning rollers 19 and a contact roller 20. As will be seen in FIG. 4, the contact roller 20, which presses the grinding band against the workpiece 4, is controlled by a feeler roller 21, which is led along a pattern 22. The pattern 22 is mounted on the workpiece holder 10. In addition, each grinding unit has a motor 23 for the driving roller 18, a guide 24 and a drive 25 to impart an oscillating band movement, a swivel bearing 26 for a tensioning arm 27 bearing one of the tension rollers 19, and finally a cross-sliding carriage 28 upon which the entire unit is adjustably mounted in relation to the rotating platform 1.

FIG. 4 shows furthermore a drive motor 29 which drives continuously the rotating platform 1 through a gear 30 only suggested. Furthermore, a frame 31 for the whole apparatus as well as a co-rotating cover lb for the rotating platform have been represented. FIG. 4 shows in addition another method of embodiment of the connection of the C-shaped stirrup 12 with the rotating platform 1. In the bottom area of its vertical leg 12b a vertical guide pin 32 is secured. The spoke 1a has a longitudinal slit 33 into which the guide pin engages, rotatable from above and guided longitudinally. The cover lb of the rotating platform has in this area also a longitudinal slit 34. For each bearing 8 a circular opening 35 has been provided.

It is clearly to be seen from FIG. 4, moreover, that the workpiece holder 10 has two form halves 10a and 10b, between which the workpiece 4 is so mounted that only its contour edge stands out. The bottom form half 10a carries in addition pattern 22.

FIG. 5 shows an enlarged view of the workpiece holder and its bearing, the latter being sectioned partly corresponding substantially to line VV of FIG. 4. The workpiece holder 10 is in its bottom area firmly connected with support 9. This is constructed in several sections and is cranked in the shape of an U, and the legs are arranged horizontally. With the vertical connection piece 9a the support is rotatably mounted in the bearing firmly fixed on the rotating table. The horizontal leg 36 mounted below this bearing and thus below the rotating platform forms a guiding roller support, on which the guiding roller 7 is rotatably mounted at a distance from the shaft 8a. As will be seen especially in FIG. 3, the guiding roller support 36 has substantially the shape of a double-pronged fork with a guide slit 37 open on one side. The second leg 38 of the support 9 is mounted over the bearing 8 parallel with the guiding roller support or crank arm 36. It rotates together with the leg 9a but is slidably connected in its longitudinal direction. A vertical bearing bolt 39 is rigidly secured on the leg 38, the axis 39a of this bolt being aligned on the axis 11a of the work-locating fixture 11. By means of the shifting of the upper leg 38 in relation to the vertical stem 90 of support 9 the distance of the axes 39a or 1 1a to the axis 8a may be modified. The bearing bolt 39 is rigidly connected with the workpiece holder 10. For the sake of clarity there has been represented in FIG. 4 by a full drawn line instead of dash-and-dot lines those shafts the contructional parts of which are rigidly, i.e., non-rotatably in relation to one another, connected. These are, from bottom to top: guide roller support 36, vertical stem 9a, upper leg 38 of the support 9, bearing bolt 39, workpiece holder 10, work-locating fixture 11. This connection is effected on the rotation of the rotating table at two places, i.e., the shaft 8a on a circular path b (FIG. 3) through the bearing 8, and the guide roller 7 through the curved tracks 5. In the areas where the curved tracks are interrupted, the guide slit 37 operates with the bolt 6 in the guise of a positive drive in a manner still to be depicted on the basis of FIG. 3. The guide roller 7 or the guide groove 37 may effect in this manner an oscillation movement of the guide roller support 36 about the shaft 8a. The same swivelling motion is performed by the upper leg 38 and the workpiece holder 10. The swivelling motion of the workpiece holder is not in this connection hindered by the C- shaped stirrup 12 of the work-locating fixture 11 swivellable only limitedly in relation to the rotating table, as the stirrup with the bearing 13 fixed on its lower leg and with its upper leg is rotatably mounted about the work-locating fixture.

FIG. 3 shows various positions of the guide roller sup port 36 in an area which begins approximately before station B and ends immediately after station D (FIG. 1 Over the guide roller support 36 the workpiece 4 is generally represented in its relevant positions by dashdot-dot lines. The circular path b, on which the shaft 8a moves, is drawn in dash and dot lines. As will be seen in FIGS. 1 and 2, the direction of the curved 'path is covered essentially by the circular path b in the area between stations H over A to station B, and then the guide roller 7 runs in front of the shaft 8a. In this position the guide roller support 36 passes station B. Between stations B and C the curve section 5 has a turning area with a switch point 40. An enlarged detailed representation of the switch point 40 is represented in FIGS. 6 and 7 and will be discussed later on the basis of said figures. In the area of the turning area the curved path runs inwards with a pronounced bend away from circular path b. In this manner it compels a deviation of the guide roller bearer by some 90. A further deviation in the same direction of rotation is produced by the fact that the guide roller moves almost radially to the center of the rotating table, while the shaft 8a continues along its circular path. The position derived from this is the third in FIG. 3, where the guide roller 7 is about to leave the switching point. On the further movement, the guide roller 7 now runs behind the shaft 8a. On passing station C the longitudinal side both of the guide roller bearer and of the workpiece holder is thus turned towards the grinding unit stationed there, the side being that which at station B was turned away from the grinding unit (fourth position). After station C the guiding curve 5 has again an inward bend, although not so pronounced as between stations B and C. Position five shows how the slit 37 is in this way positively passed over the bolt 6. When the guide roller 7 comes out of the curved path 5 the bolt 6 cooperates with the slit 37 in such a way that the guide roller support performs a swivelling movement around the bolt 6 (position six). At the end of this swivelling movement the guide roller 7 is introduced into the curved path section beginning in front of station D. Thereby the guide roller support moves again forward with the guide roller onto station D (position sei/en).

The processing of the workpiece 4 during the movement cycle which has just been described is carried out in a way that the spoon, positioned in the area of station A, where the workpiece holder is guided substantially parallel to the contour, with the handle end substantially above the guide roller 7 and with its bowl substantially above the shaft 8, is brought up with the handle end in front of the grinding unit 3a located at station B. Thereby at the same time the grinding band, pressed by its contact roller 20 more or less in the middle of the front side of the spoon handle, comes in contact with the latter and at the same time the feeler roller 21 comes in contact with pattern 22 at a corresponding position. While now the spoon moves past the grinding unit along the same direction as the guide roller carrier 36, its fully extended longitudinal side in position one of FIG. 3 and the connecting half of the front side at the bowl end are processed. This front side portion can be processed in that at the end of the range of action of the grinding unit the swivelling movement into position two has already begun. In the same way the second half of the contour edge is processed at station C. The grinding unit of station C comes into action at the middle of the front edge of the bowl side and processes the longitudinal side turned towards it including the second front edge half at the spoon handle end which slides past it during the swivelling movement between positions four and five. The contour edge area processed at station C is represented in position four as a full line.

FIG. 6 shows a switching point 40 with a guide roller 7 in three different positions. The switching point 40 comprises a generally Y-shaped junction having a pair of leg portions 40A and 40B and a stem portion 4C. A gate or lever 42 is pivotally mounted on a shaft 41a located adjacent the intersection between the legs and the stem and extends partially coextensively with the stem 40C. A piece of curve 41 is on the gate is held in the position represented in FIG. 6 with solid lines by means of a spring 43. The oncoming guide roller 7 presses the curve portion 41, while it rolls on along the curve 44 turned towards it, in the second final position which has been represented by dot-dash lines. In this position the piece of curve 41 remains until the guide roller 7 moves on from its position three represented in the direction of the arrow in curved track 5. Then the piece of curve 41 swivels under the action of the spring 43 back to its starting position. If now the guide roller 7, during its further movement effected by the rotation of the platform 1 and against the direction of the arrow, moves again into position three, it rolls along the curved surface 45 of the piece of curve 41. This position is represented in the cross-section of FIG. 7. The section of curve 41 is forked at its free end into an upper point 41b and a lower point 410. The curved track has recesses 46 and 47 for the movement of these points. In the basic position the outside of the lower point 41 lies against the wall of this recess, so that the roller rolling along the curve 45 finds a positive stop. When on running into the switch point the roller 7 deviates the portion of curve 41 to its second position, the upper point 41b applies itself with its inner side in normal position against the wall of the curved track 5, so that the guide roller 7 rolling on the curve 44 is positively supported. The lower point 410 locates itself in the recess 47. As shown in FIGS. 2 and 3, the guide roller carrier is introduced with the guide roller in front into the switch point. A pressure exerted substantially in that area still by the processing tool operates therefore in the sense of the switching of the switch point.

The invention is not restricted to the examples of execution. Thus, in particular, there can be provided on an apparatus not only a single processing station with two grinding units but also more than three processing stations. The rotating platform may consist, instead of one spoked spider, in a solid or annular shaped plate. Instead of the bolts effecting the deviation between the sections of curved track further curved track sections may be provided. The grinding units may be provided with resilient grinding discs instead of grinding bands. It is furthermore possible to mount, instead of grinding units, other tools controlled by means of contact rollers.

We claim: I I. In a device for grinding the peripheral edge on an elongated workpiece having table means and first support means for supporting said table means for a continuous rotation, workpiece holding means mounted on said table means for movement therewith and adapted to hold said workpiece thereon, at least two grinding units circumferentially spaced about the periphery of said table means and adapted to periodically engage said workpiece and stationary track means for controlling the position of said workpiece relative to said grinding units, the improvement comprising:

second support means for rotatably supporting workpiece holding means for rotatable movement about an axis separate from and parallel to the axis of said first support means; crank arm means secured to said workpiece holding means and including follower means mounted on said crank arm means and engaging said track means; switching means on said track means and engageable by said follower means for effecting a rotational movement of said workpiece holding means and consequently saidworkpiece to present an opposite peripheral edge on said workpiece to one of said grinding units following a grinding of one peripheral edge by the other of said grinding units; and template means mounted on said workpiece holding means and having a desired peripheral edge contour; and grinding unit support means for supporting each of said grinding units for movement relative to said table means and movement toward and away from said workpiece, said grinding unit support means including template engaging means for engaging said template means and thereby controlling the movement of said grinding unit support means and said grinding unit whenever said workpiece holding means is positioned adjacent said grinding unit.

2. The improvement according to claim 1, wherein said grinding unit support means supports said grind unit for a pivotal movement toward and away from said workpiece.

3. The improvement according to claim 2, wherein said switching means is adapted to effect a rotatable movement of said workpiece holding means about an approximate angle.

4. The improvement according to claim 1 wherein said switching means is positioned between said grinding units; and

wherein said first support means supports said table means for movement in one rotational direction.

5. The improvement according to claim 1, wherein said switching means comprises a generally Y-shaped junction in said track means having a pair of leg portions and a stem portion extending away from said leg portions and pivotal gate means adapted to pivot upon engagement by said follower means out of the way during a movement of said table means relative to said track means and a corresponding movement of said follower means from one of said leg portions to said stem portion, said gate means, upon a continued movement of said table means blocking the movement of said follower means along a return path and directing said follower means from said stem portion to the other of said leg portions.

6. The improvement according to claim 5, wherein a curved piece on said gate for guiding said follower means is divided at its free end into an upper part and a lower part, said parts being spread out horizontally away from each other.

7. The improvement according to claim 1, wherein said switching means comprises a bolt secured to said track means and between a pair of open ends in said track means; and

wherein said crank arm means comprises a crank arm and means defining a slot in an end thereof remote from said follower means and adapted to receive said bolt therein, a movement of said table means relative to said bolt, when said bolt is received in said slot, effecting a rotation of said crank arm and said workpiece.

8.'The improvement according to claim 1, wherein said workpiece holding means comprises bearing meansfor supporting a shaft means having an axis of rotation parallel to the axis of rotation of said table means, said crank arm means being positioned below said table means, said workpiece holding means being fixed to and extending above said table means.

9. The improvement according to claim 8, wherein said shaft means is a substantially U-shaped crank having an upper leg and a lower leg connected by a vertical shaft, the lower leg being defined by said crank arm means and the upper leg being aligned with said lower leg and extendsin the same longitudinal direction as said crank arm means over the latter.

10. The improvement according to claim 9, wherein said upper leg is adjustable in length according to the size of the workpiece.

11. The improvement according to claim 1, wherein said workpiece holding means is associated with a work-locating fixture having a stirrup surrounding it which is substantially C-shaped, said stirrup being rotatable while engaging said workpiece holding means about a vertical axis, the work-locating fixture being rotatably mounted on said table means about a longitudinally displaceable vertical axis.

12. The improvement according to claim 1 1, wherein said C-shaped stirrup has horizontally aligned upper and lower legs connected by a vertical leg, said lower leg being mounted on a bearing bolt and said upper leg being rotatably mounted on said work-locating fixture about an axis aligned with the axis of said bearing bolt.

13. The improvement according to claim 11, wherein said C-shaped stirrup has a guiding pin in the area of said vertical leg said table means having a radial slit therein adapted to receive said guide pin for guiding said guide pin.

14. The improvement according to claim 11, wherein said table means has means defining a centrally mounted pin and wherein said stirrup has a guiding arm having means defining a longitudinal groove therein adapted to receive said pin.

15. The improvement according to claim 1, wherein said workpiece which cause the workpiece to expose a peripheral edge for machining by said grinding unit.

16. The improvement according to claim 1, wherein said grinding unit comprises a grinding band adapted to rotate on the same plane as said workpiece, said grinding unit includes means for pressing said band against the workpiece and means defining a contact roller controlled by a feeler roller for controlling the engagement of said band with said workpiece.

17. The improvement according to claim 16, wherein said template means comprises a template mounted on the workpiece holding means in alignment with said form halves.

18. The improvement according to claim 16, wherein said grinding unit includes adjustable means for adjusting the range of movement according to the size of the workpiece. 

1. In a device for grinding the peripheral edge on an elongated workpiece having table means and first support means for supporting said table means for a continuous rotation, workpiece holding means mounted on said table means for movement therewith and adapted to hold said workpiece thereon, at least two grinding units circumferentially spaced about the periphery of said table means and adapted to periodically engage said workpiece and stationary track means for controlling the position of said workpiece relative to said grinding units, the improvement comprising: second support means for rotatably supporting workpiece holding means for rotatable movement about an axis separate from and parallel to the axis of said first support means; crank arm means secured to said workpiece holding means and including follower means mounted on said crank arm means and engaging said track means; switching means on said track means and engageable by said follower means for effecting a rotational movement of said workpiece holding means and consequently said workpiece to present an opposite peripheral edge on said workpiece to one of said grinding units following a grinding of one peripheral edge by the other of said grinding units; and template means mounted on said workpiece holding means and having a desired peripheral edge contour; and grinding unit support means for supporting each of said grinding units for movement relative to said table means and movement toward and away from said workpiece, said grinding unit support means including template engaging means for engaging said template means and thereby controlling the movement of said grinding unit support means and said grinding unit whenever said workpiece holding means is positioned adjacent said grinding unit.
 2. The improvement according to claim 1, wherein said grinding unit support means supports said grind unit for a pivotal movement toward and away from said workpiece.
 3. The improvement according to claim 2, wherein said switching means is adapted to effect a rotatable movement of said workpiece holding means about an approximate 180* angle.
 4. The improvement according to claim 1, wherein said switching means is positioned between said grinding units; and wherein said first support means supports said table means for movement in one rotational direction.
 5. The improvement according to claim 1, wherein said switching means comprises a generally Y-shaped junction in said track means having a pair of leg portions and a stem portion extending away from said leg portions and pivotal gate means adapted to pivot upon engagement by said follower means out of the way during a movement of said table means relative to said track means and a corresponding movement of said follower means from one of said leg portions to said stem portion, said gate means, upon a continued movement of said table means blocking the movement of said follower means along a return path and directing said follower means from said stem portion to the other of said leg portions.
 6. The improvement according to claim 5, wherein a curved piece on said gate for guiding said follower means is divided at its free end into an upper part and a lower part, said parts being spread out horizontally away from each other.
 7. The improvement according to claim 1, wherein said switching means comprises a bolt secured to said track means and between a pair of open ends in said track means; and wherein said crank arm means comprises a crank arm and means defining a slot in an end thereof remote from said follower means and adapted to receive said bolt therein, a movement of said table means relative to said bolt, when said bolt is received in said slot, effecting a rotation of said crank arm and said workpiece.
 8. The improvement according to claim 1, wherein said workpiece holding means comprises bearing means for supporting a shaft means having an axis of rotation parallel to the axis of rotation of said table means, said crank arm means being positioned below said table means, said workpiece holding means being fixed to and extending above said table means.
 9. The improvement according to claim 8, wherein said shaft means is a substantially U-shaped crank having an upper leg and a lower leg connected by a vertical shaft, the lower leg being defined by said crank arm means and the upper leg being aligned with said lower leg and extends in the same longitudinal direction as said crank arm means over the latter.
 10. The improvement according to claim 9, wherein said upper leg is adjustable in length according to the size of the workpiece.
 11. The improvement according to claim 1, wherein said workpiece holding means is associated with a work-locating fixture having a stirrup surrounding it which is substantially C-shaped, said stirrup being rotatable while engaging said workpiece holding means about a vertical axis, the work-locating fixture being rotatably mounted on said table means about a longitudinally displaceable vertical axis.
 12. The improvement according to claim 11, wherein said C-shaped stirrup has horizontally aligned upper and lower legs connected by a vertical leg, said lower leg being mounted on a bearing bolt and said upper leg being rotatably mounted on said work-locating fixture about an axis aligned with the axis of said bearing bolt.
 13. The improvement according to claim 11, wherein said C-shaped stirrup has a guiding pin in the area of said vertical leg, said table means having a radial slit therein adapted to receive said guide pin for guiding said guide pin.
 14. The improvement according to claim 11, wherein said table means has means defining a centrally mounted pin and wherein said stirrup has a guiding arm having means defining a longitudinal groove therein adapted to receive said pin.
 15. The improvement according to claim 1, wherein said workpiece holding means has interchangeable forming halves which cause the workpiece to expose a peripheral edge for machining by said grinding unit.
 16. The improvement according to claim 1, wherein said grinding unit comprises a grinding band adapted to rotate on the same plane as said workpiece, said grinding unit includes means for pressing said band against the workpiece and means defining a contact roller controlled by a feeler roller for controlling the engagement of said band with said workpiece.
 17. The improvement according to claim 16, wherein said template means comprises a template mounted on the workpiece holding means in alignment with said form halves.
 18. The improvement according to claim 16, wherein said grinding unit includes adjustable means for adjusting the range of movement according to the size of the workpiece. 